mcs/class/corlib/System.Threading/ExecutionContext.cs

   1 //
   2 // System.Threading.ExecutionContext.cs
   3 //
   4 // Authors:
   5 //      Lluis Sanchez (lluis@novell.com)
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System.Runtime.InteropServices;
  31 using System.Runtime.Serialization;
  32 using System.Security;
  33 using System.Security.Permissions;
  34 using System.Runtime.Remoting.Messaging;
  35
  36 namespace System.Threading {
  37         [Serializable]
  38         public sealed class ExecutionContext : ISerializable
  39 #if NET_4_0
  40                 , IDisposable
  41 #endif
  42         {
  43 #if !MOBILE
  44                 private SecurityContext _sc;
  45 #endif
  46                 private LogicalCallContext _lcc;
  47                 private bool _suppressFlow;
  48                 private bool _capture;
  49
  50                 internal ExecutionContext ()
  51                 {
  52                 }
  53
  54                 internal ExecutionContext (ExecutionContext ec)
  55                 {
  56 #if !MOBILE
  57                         if (ec._sc != null)
  58                                 _sc = new SecurityContext (ec._sc);
  59 #endif
  60                         _suppressFlow = ec._suppressFlow;
  61                         _capture = true;
  62                 }
  63
  64                 [MonoTODO]
  65                 internal ExecutionContext (SerializationInfo info, StreamingContext context)
  66                 {
  67                         throw new NotImplementedException ();
  68                 }
  69
  70                 public static ExecutionContext Capture ()
  71                 {
  72                         return Capture (true);
  73                 }
  74
  75                 internal static ExecutionContext Capture (bool captureSyncContext)
  76                 {
  77                         ExecutionContext ec = Thread.CurrentThread.ExecutionContext;
  78                         if (ec.FlowSuppressed)
  79                                 return null;
  80
  81                         ExecutionContext capture = new ExecutionContext (ec);
  82 #if !MOBILE
  83                         if (SecurityManager.SecurityEnabled)
  84                                 capture.SecurityContext = SecurityContext.Capture ();
  85 #endif
  86
  87 #if !MONOTOUCH
  88                         capture.LogicalCallContext = CallContext.CreateLogicalCallContext (false);
  89 #endif
  90                         return capture;
  91                 }
  92
  93                 public ExecutionContext CreateCopy ()
  94                 {
  95                         if (!_capture)
  96                                 throw new InvalidOperationException ();
  97
  98                         return new ExecutionContext (this);
  99                 }
 100
 101 #if NET_4_0
 102                 public void Dispose ()
 103                 {
 104 #if !MOBILE
 105                         if (_sc != null)
 106                                 _sc.Dispose ();
 107 #endif
 108                 }
 109 #endif
 110
 111                 [MonoTODO]
 112                 [ReflectionPermission (SecurityAction.Demand, MemberAccess = true)]
 113                 public void GetObjectData (SerializationInfo info, StreamingContext context)
 114                 {
 115                         if (info == null)
 116                                 throw new ArgumentNullException ("info");
 117                         throw new NotImplementedException ();
 118                 }
 119
 120                 // internal stuff
 121
 122                 internal LogicalCallContext LogicalCallContext {
 123                         get {
 124                                 if (_lcc == null)
 125                                         return new LogicalCallContext ();
 126                                 return _lcc;
 127                         }
 128                         set {
 129                                 _lcc = value;
 130                         }
 131                 }
 132
 133 #if !MOBILE
 134                 internal SecurityContext SecurityContext {
 135                         get {
 136                                 if (_sc == null)
 137                                         _sc = new SecurityContext ();
 138                                 return _sc;
 139                         }
 140                         set { _sc = value; }
 141                 }
 142 #endif
 143
 144                 internal bool FlowSuppressed {
 145                         get { return _suppressFlow; }
 146                         set { _suppressFlow = value; }
 147                 }
 148
 149                 // Note: Previous to version 2.0 only the CompressedStack and (sometimes!) the WindowsIdentity
 150                 // were propagated to new threads. This is why ExecutionContext is internal in before NET_2_0.
 151                 // It also means that all newer context classes should be here (i.e. inside the #if NET_2_0).
 152
 153                 public static bool IsFlowSuppressed ()
 154                 {
 155                         return Thread.CurrentThread.ExecutionContext.FlowSuppressed;
 156                 }
 157
 158                 public static void RestoreFlow ()
 159                 {
 160                         ExecutionContext ec = Thread.CurrentThread.ExecutionContext;
 161                         if (!ec.FlowSuppressed)
 162                                 throw new InvalidOperationException ();
 163
 164                         ec.FlowSuppressed = false;
 165                 }
 166
 167                 [MonoTODO ("only the SecurityContext is considered")]
 168                 [SecurityPermission (SecurityAction.LinkDemand, Infrastructure = true)]
 169                 public static void Run (ExecutionContext executionContext, ContextCallback callback, object state)
 170                 {
 171                         if (executionContext == null) {
 172                                 throw new InvalidOperationException (Locale.GetText (
 173                                         "Null ExecutionContext"));
 174                         }
 175
 176 #if MOBILE
 177                         callback (state);
 178 #else
 179                         // FIXME: supporting more than one context should be done with executionContextSwitcher
 180                         // and will requires a rewrite of this method
 181                         var callContextCallBack = new ContextCallback (new Action<object> ((ostate) => {
 182                                 var originalCallContext = CallContext.CreateLogicalCallContext (true);
 183                                 try {
 184                                         CallContext.SetCurrentCallContext (executionContext.LogicalCallContext);
 185                                         callback (ostate);
 186                                 } finally {
 187                                         CallContext.SetCurrentCallContext (originalCallContext);
 188                                 }
 189                         }));
 190                         SecurityContext.Run (executionContext.SecurityContext, callContextCallBack, state);
 191 #endif
 192                 }
 193
 194                 public static AsyncFlowControl SuppressFlow ()
 195                 {
 196                         Thread t = Thread.CurrentThread;
 197                         t.ExecutionContext.FlowSuppressed = true;
 198                         return new AsyncFlowControl (t, AsyncFlowControlType.Execution);
 199                 }
 200         }
 201 }